Buster, a 2-year-old, intact, male mixed-breed dog was adopted from a local shelter and presented to the veterinary clinic for health evaluation and neuter operation.
History. Buster has no obvious medical problems. Before he was placed at the shelter, he lived on a farm in the Midwest and was primarily an outdoor dog. According to the owners, he runs in the local woods and is known to scavenge dead animals and eat other things he may find. His vaccinations are current, but he has not been on a heartworm preventative.
Physical Examination. Buster appears to be in overall good health. Centrifugal flotation is used to examine a fecal sample for parasites, and a heartworm antigen test is performed. The technician notes two types of eggs, Toxocara canis and smaller, unfamiliar ones. Figure 1 shows what she saw with her microscope. The veterinarian also looks at the slide and confirms the presence of the unusual parasite eggs. Buster is to be treated 3 times with a broad-spectrum anthelmintic on a 2-week schedule, and a follow-up fecal examination is scheduled for the next visit in 2 weeks. On that fecal examination, no parasite eggs are seen. The heartworm test is negative, and Buster is started on a monthly heartworm preventative that also removes intestinal nematodes. The neuter operation is uneventful. Two days after the first deworming, Buster sheds numerous roundworms in his feces, which the owner picks up and disposes of in the trash as directed by the veterinarian.
ASK YOURSELF ...
- What are the relative sizes and other microscopic features of the eggs present?
- Are there other parasites that could appear similar on a fecal examination?
- Besides treatment, what other recommendations should be made in this case?
Eggs of B. procyonis (smaller, darker) and T. canis from the feces of a dog (407x original magnification)